Faraday’s Law of Induction

• Magnetic flux (Φ): Amount of magnetic field through an area. Visualize a “magnetic field lines.”
• EMF (ε): Voltage from changing magnetic flux. Imagine being shocked by a suddenly moving magnet.
• Lenz’s law: Induced EMF “fights back” against flux changes. Right-hand rule shows its direction.
• Faraday’s law: Rate of flux change directly gives induced EMF. It’s like measuring water flow rate.

Mutual Inductance (M)

• Ratio of induced EMF in one coil due to the change in current of another to the rate of change of that current.
• Formula: $$M=\frac{\mu_0 N_1 N_2 A}{l}$$
• Breakdown: M in Henry (H) is incorrect; the symbol for the unit of magnetic flux density is Weber (Wb), and the symbol for magnetic field strength is Tesla (T). The unit Henry (H) is used for inductance.
• μ0 is the permeability of free space (4π × 10-7 T m/A).
• N1, N2 are coil turns.
• A is coil area in square meters.
• l is coil length in meters.

Self-Inductance (L)

• Ratio of back EMF in a coil to the rate of change of current.
• Formula: $$L= \frac{\mu_0 N^2 A}{l}$$
• Breakdown: L in Henry (H) unit.
• μ0 is the permeability of free space (4π × 10-7 T m/A).
• N is the number of turns in the coil.
• A is the cross-sectional area of the coil in square meters.
• l is the length of the coil in meters.